Osprey's fishing technique (1 Viewer)

[Mark B Bartosik]

During this winter we have many Ospreys along the Upper and Lower Texas Coast so I finally decided to spend more time with them and try to document on photographs their fishing techniques. I visited many locations and spent many hours just watching them taking fish from the water. In fact this project took most of my 'free' time in December. Easy access location closest to Houston is Salt Lake at Brazoria National Wildlife Refuge but many photographs were taken in other locations between Galveston and Laguna Atascosa National Wildlife Refuge. In fact LANWR is a premier place to find and observe Ospreys in the winter.

Most internet sites, as well as many books, describing details of Osprey hunting techniques not quite precisely which can make a false picture in reader’s mind, especially one who never had a chance to observe hunting Osprey from the close distance. As in the past I only saw them fishing on rare occasion, usually way too far to take decent photograph, I kept promising myself to find time and dedicate it just for fishing Ospreys. Here I will try to show every important moment illustrating phases of the hunt. Action is very similar every time when Osprey decide to try catch a fish but I never ever can imagine to possibly get bored when see it again and again.

First phase of the hunt is easy and well described everywhere: Osprey will either start watching for fish from the perch near water (http://www.pbase.com/mbb/image/72689366, http://www.pbase.com/mbb/image/72689367) or will take a fly over water body and flying slowly will keep looking for a prey (http://www.pbase.com/mbb/image/72689412).

Next phase is when fish is spotted. Usually bird will start hovering for a few seconds observing potential prey. (http://www.pbase.com/mbb/image/72689378) Even when hunting from perch Osprey will initially fly over the place when fish was seen and might hover for a moment before making decision to go after it.

Now a real fun to watch is beginning. http://www.pbase.com/mbb/image/72689380

Osprey will fold its wings close to its body and start going down on the high-speed dive. (http://www.pbase.com/mbb/image/72689430).
http://www.pbase.com/mbb/image/72689431
Fish might see this:
http://www.pbase.com/mbb/image/72689425

Once in the chasing dive only on a very few occasions bird will decide not to hit the water and will came out from a dive just above the surface. Loosing the sight of fish or seeing dangerous obstruction/shallow water? I can not tell.

But back to the air dive. When getting close to the water surface Osprey will start getting its talons ready. http://www.pbase.com/mbb/image/72689426
http://www.pbase.com/mbb/image/72689427

And the last moment of the air dive is a moment that is most often not precisely described. Most sites\books will say that bird will get to water feet (talons) first. Technically correct but only by matter of a couple inches. Calling it 'talons-head-first' seems to be more accurate but only a very few authors are doing that. Look here, it is always the same. (http://www.pbase.com/mbb/image/72689434) At very last moment before plunging into the water Osprey will extend its neck and place its head together with talons, its bill only a few inches behind the claws. Wings will go even closer to the body and way up back making the bird looking like an arrowhead. In this assault pose Osprey will come with contact with the water. In all cases (many) I observed its whole body, extended wings included, will go completely under the water creating a huge water splash above. (http://www.pbase.com/mbb/image/72689369) Note here: some authors create impression that Ospreys take their prey from the water surface. Many taken photographs are showing Osprey just coming out of water with fish (beautiful moment, so very popular and prized on photos) it help also to create illusion of Osprey snatching its prey just from the surface. I never saw one single dive when bird was not completely under water when diving into the surface. With data stating very high speed (clocked over 40 miles/hour) plus the shape of the body during final stage I can not imagine it is possible for Osprey to stay even partially above the water surface when plunging into the water. But several sources say: "On occasion, osprey will immerse entirely in the water, a rare behavior for raptors." As I already said I did not see even one single case when not entire Osprey body was submerge in the water when plunging. Any reader has different observation?

Note here: not every attack is successful. I observed similar rate, about 1 in 5, to other authors. With or without fish bird will come back to the water surface. In a split second after water dive, often when big water splash is still up, tips of the Osprey’s wings will come above (http://www.pbase.com/mbb/image/72689370), then more wings (http://www.pbase.com/mbb/image/72689372) and the head. Just when head will emerge Osprey will make first shake removing some water from its head. (http://www.pbase.com/mbb/image/72689403) With whole wings above the water, still chest deep http://www.pbase.com/mbb/image/72689383 submerged in the water Osprey will give a powerful swing taking its body (again with http://www.pbase.com/mbb/image/72689437 or without fish http://www.pbase.com/mbb/image/72689432) completely out of the water. http://www.pbase.com/mbb/image/72689439

After gaining some distance from the water Osprey will shake its whole body (up to a few times) removing the water. http://www.pbase.com/mbb/image/72689436
http://www.pbase.com/mbb/image/72689414

It will place prey headfirst (especially larger fish ), even when head is already gone, http://www.pbase.com/mbb/image/72689423 to reduce drag during a fly and then try to find a place to eat it.

Often when getting wet after many dive attempts Osprey after shaking the body in mid-air will also try to find the place to perch with wing spread to dry the plumage even more. http://www.pbase.com/mbb/image/72689419
http://www.pbase.com/mbb/image/72689420

And just a few extra notes for those few readers who never were interested in Ospreys before. This raptor has unique talons much better adopted to catching and holding prey that many other birds of prey. Its outer toes are reversible, allowing bird to grip fish with 2 toes forward and 2 back providing extra balance.
http://www.pbase.com/mbb/image/72689422
http://www.pbase.com/mbb/image/72689443
Also Ospreys have backwards facing scales on the talons which act as barbs to help hold its catch.

Of course, like any other food, fish is digested and leftovers defecated. http://www.pbase.com/mbb/image/72689365
Non digestive parts are 'cast'. Here Osprey is trying to cast a pellet.
http://www.pbase.com/mbb/image/72689364

I am very satisfy with many observations but happiness rarely is complete. Many photos were taken during dense morning fog or sea fog rolling over the shore. One of extreme but often cases http://www.pbase.com/mbb/image/72689368. I only hope that one day I will have a chance to catch this magnificent bird fishing in much better light to duplicate some of the frames again.

I will also appreciate a lot if readers can share more/additional information about observed Osprey's fishing behaviors.

For those who want to see more of photos please go directly to this folder:
http://www.pbase.com/mbb/utc_december_2006_osprey


All the best,

Mark

 

[john-henry]

During this winter we have many Ospreys along the Upper and Lower Texas Coast so I finally decided to spend more time with them and try to document on photographs their fishing techniques. I visited many locations and spent many hours just watching them taking fish from the water. In fact this project took most of my 'free' time in December. Easy access location closest to Houston is Salt Lake at Brazoria National Wildlife Refuge but many photographs were taken in other locations between Galveston and Laguna Atascosa National Wildlife Refuge. In fact LANWR is a premier place to find and observe Ospreys in the winter.

Most internet sites, as well as many books, describing details of Osprey hunting techniques not quite precisely which can make a false picture in reader’s mind, especially one who never had a chance to observe hunting Osprey from the close distance. As in the past I only saw them fishing on rare occasion, usually way too far to take decent photograph, I kept promising myself to find time and dedicate it just for fishing Ospreys. Here I will try to show every important moment illustrating phases of the hunt. Action is very similar every time when Osprey decide to try catch a fish but I never ever can imagine to possibly get bored when see it again and again.

First phase of the hunt is easy and well described everywhere: Osprey will either start watching for fish from the perch near water (http://www.pbase.com/mbb/image/72689366, http://www.pbase.com/mbb/image/72689367) or will take a fly over water body and flying slowly will keep looking for a prey (http://www.pbase.com/mbb/image/72689412).

Next phase is when fish is spotted. Usually bird will start hovering for a few seconds observing potential prey. (http://www.pbase.com/mbb/image/72689378) Even when hunting from perch Osprey will initially fly over the place when fish was seen and might hover for a moment before making decision to go after it.

Now a real fun to watch is beginning. http://www.pbase.com/mbb/image/72689380

Osprey will fold its wings close to its body and start going down on the high-speed dive. (http://www.pbase.com/mbb/image/72689430).
http://www.pbase.com/mbb/image/72689431
Fish might see this:
http://www.pbase.com/mbb/image/72689425

Once in the chasing dive only on a very few occasions bird will decide not to hit the water and will came out from a dive just above the surface. Loosing the sight of fish or seeing dangerous obstruction/shallow water? I can not tell.

But back to the air dive. When getting close to the water surface Osprey will start getting its talons ready. http://www.pbase.com/mbb/image/72689426
http://www.pbase.com/mbb/image/72689427

And the last moment of the air dive is a moment that is most often not precisely described. Most sites\books will say that bird will get to water feet (talons) first. Technically correct but only by matter of a couple inches. Calling it 'talons-head-first' seems to be more accurate but only a very few authors are doing that. Look here, it is always the same. (http://www.pbase.com/mbb/image/72689434) At very last moment before plunging into the water Osprey will extend its neck and place its head together with talons, its bill only a few inches behind the claws. Wings will go even closer to the body and way up back making the bird looking like an arrowhead. In this assault pose Osprey will come with contact with the water. In all cases (many) I observed its whole body, extended wings included, will go completely under the water creating a huge water splash above. (http://www.pbase.com/mbb/image/72689369) Note here: some authors create impression that Ospreys take their prey from the water surface. Many taken photographs are showing Osprey just coming out of water with fish (beautiful moment, so very popular and prized on photos) it help also to create illusion of Osprey snatching its prey just from the surface. I never saw one single dive when bird was not completely under water when diving into the surface. With data stating very high speed (clocked over 40 miles/hour) plus the shape of the body during final stage I can not imagine it is possible for Osprey to stay even partially above the water surface when plunging into the water. But several sources say: "On occasion, osprey will immerse entirely in the water, a rare behavior for raptors." As I already said I did not see even one single case when not entire Osprey body was submerge in the water when plunging. Any reader has different observation?

Note here: not every attack is successful. I observed similar rate, about 1 in 5, to other authors. With or without fish bird will come back to the water surface. In a split second after water dive, often when big water splash is still up, tips of the Osprey’s wings will come above (http://www.pbase.com/mbb/image/72689370), then more wings (http://www.pbase.com/mbb/image/72689372) and the head. Just when head will emerge Osprey will make first shake removing some water from its head. (http://www.pbase.com/mbb/image/72689403) With whole wings above the water, still chest deep http://www.pbase.com/mbb/image/72689383 submerged in the water Osprey will give a powerful swing taking its body (again with http://www.pbase.com/mbb/image/72689437 or without fish http://www.pbase.com/mbb/image/72689432) completely out of the water. http://www.pbase.com/mbb/image/72689439

After gaining some distance from the water Osprey will shake its whole body (up to a few times) removing the water. http://www.pbase.com/mbb/image/72689436
http://www.pbase.com/mbb/image/72689414

It will place prey headfirst (especially larger fish ), even when head is already gone, http://www.pbase.com/mbb/image/72689423 to reduce drag during a fly and then try to find a place to eat it.

Often when getting wet after many dive attempts Osprey after shaking the body in mid-air will also try to find the place to perch with wing spread to dry the plumage even more. http://www.pbase.com/mbb/image/72689419
http://www.pbase.com/mbb/image/72689420

And just a few extra notes for those few readers who never were interested in Ospreys before. This raptor has unique talons much better adopted to catching and holding prey that many other birds of prey. Its outer toes are reversible, allowing bird to grip fish with 2 toes forward and 2 back providing extra balance.
http://www.pbase.com/mbb/image/72689422
http://www.pbase.com/mbb/image/72689443
Also Ospreys have backwards facing scales on the talons which act as barbs to help hold its catch.

Of course, like any other food, fish is digested and leftovers defecated. http://www.pbase.com/mbb/image/72689365
Non digestive parts are 'cast'. Here Osprey is trying to cast a pellet.
http://www.pbase.com/mbb/image/72689364

I am very satisfy with many observations but happiness rarely is complete. Many photos were taken during dense morning fog or sea fog rolling over the shore. One of extreme but often cases http://www.pbase.com/mbb/image/72689368. I only hope that one day I will have a chance to catch this magnificent bird fishing in much better light to duplicate some of the frames again.

I will also appreciate a lot if readers can share more/additional information about observed Osprey's fishing behaviors.

For those who want to see more of photos please go directly to this folder:
http://www.pbase.com/mbb/utc_december_2006_osprey


All the best,

Mark

Thank you Mark for an enlightening insight into Ospreys, your patience and dedication is obvious for all to see, and with the excellent photographs and knowledge gained you must feel very rewarded for all the time you put in.

Thank you once again for sharing your experiences, many of us hardly ever see an Osprey let alone get the chance to photograph or watch them closely.

As for your photographs, superb, absolutely superb.

Best wishes

John

 

[Chris Monk]

Thank you Mark for an enlightening insight into Ospreys, your patience and dedication is obvious for all to see, and with the excellent photographs and knowledge gained you must feel very rewarded for all the time you put in.

Thank you once again for sharing your experiences, many of us hardly ever see an Osprey let alone get the chance to photograph or watch them closely.

As for your photographs, superb, absolutely superb.

Best wishes

John

Mark,

Can I echo John's words and ask if you would mind if I forwarded your posting onto the Rutland Water Osprey web site http://www.ospreys.org.uk/ for their use?

Cheers,
Chris

 

[Mark B Bartosik]

John and Chris thank you very much for your kind words. Chris this site looks very interesting – I will have no problem if they use my posting. Only one condition. The have to correct my grammar if they want to display it permanently. : )

And a few more words. So far from emails replies I learned that everyone who had chance to observe fishing Ospreys always saw them submerging completely under the water after the plunge. Also, as I was afraid, some people had false picture of Ospreys only snatching fish from the surface and they was writing me how shocking it was to them to see my photos. So far, so good.

All the best,

Mark

 

[deborah4]

At the risk of being unimaginative, let me also echo John's words! Mark, I was particularly interested to note that the Osprey secures and takes off with it's catch with one talon. It doesn't appear to use the other until it's in 'full flight' mode. Is this usual from your obs? Also, this led me to wonder if the choice of talon is random, or is there suggestion that BoPs will use preferential talons (or are completely ampidexterous (sp?))

 

[talon_dfa]

... I was particularly interested to note that the Osprey secures and takes off with it's catch with one talon....this led me to wonder if the choice of talon is random, or is there suggestion that BoPs will use preferential talons (or are completely [ambidextrous])...

I have seen Osprey come out of the water holding a fish with both talons...

As seen in Mark B's pics, they definitely hit the water with both feet committed (Great pics by the way - and thanks for your efforts to contribute to knowledge of Osprey).

It is probably a matter of luck whether fish is snagged with one or both feet...

I will be curious to see if Mark (or anyone else) has noticed a tendency of individuals to use one foot.

I have noticed that captive raptors sometimes have a tendency to use one foot more than the other (one to hold small prey item - the other to stand).

 

[Mark B Bartosik]

Thanks again everyone for adding information to the post. I would guess that using left or right talon is a random choice (but I observed very close only several takes off with fish not enough to draw conclusions). Also I have seen photographs when Osprey was catching two fish in the same time, one in each talon. I would guess again that this is more a case of luck with very dense fish concentration in the spot of plunge rather than planned pursuit under the water.

I had only chance to photograph birds taking relatively small fish, so using one talon was more then enough. I will think that with large fish they not only will need both talons to catch and lift but also will strike them with both talons – Osprey are known to take fish up to 4 pounds, that is quite large fish. Again on photos I have seen when Osprey is lifting from water with large fish it holds it with both talons.

All the best,

Mark

 

[TBMike]

I have Osprey fishing out back here from time to time and I have only see the catch completely once. I was surprised to see him go under as Mark states. Usually time I hear and turn to see he is out of water and leaving with catch or empty handed.
Fun to watch and surprising to see it re emerge from the water.

 

[Andy in West Oz]

Amazing serties of photos and very detailed notes Mark, thank you for taking the time to put them up. Do you mind if I pass the post onto the editor of Boobook, the Australasian Raptor Association's magazine? He'll be interested to see it.

Cheers

Andy

 

[KC Foggin]

A wonderful pictorial essay Mark. You should be quite proud of this.

Somewhere I have a photo taken a few years back of a juvenile osprey that I watched take several dives and come up with nothing. Finally, he just stayed in the water and watched. It was quite comical to watch.

 

[Mark B Bartosik]

Thanks Andy an KC.

Andy it will be my pleasure.

Cheers

Mark

 

[Andy in West Oz]

Thanks Mark.

 

[Scotsdumpie]

Ospreys have the ability to reverse their outer claw on their talons so giving a full pincer grip on contact supposidly a reflex action, feet rough and scaley
Also all underside feathering is tight and legs long and short of feathering
It has nostrils that close underwater and for a bird of a wingspan of oven 5feet it weighs an astonishingly light 3 1/2 lbs ,,a number lost in migration , likely due to wide and weather particularly in first year can lift at least its own body weight from the water
Scotland did a census for the 50th aniversary of the Osprey returning to Scotland in 2005 we had 224 chicks away that season and hopefully we expect approaching half back next year maybee !!?!!


Sennnnsational fhotties by the way (fhottiegraffs)